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dc.contributor.advisorWash, Carlyle H.
dc.contributor.authorDykes, James D.
dc.dateMarch 1991
dc.date.accessioned2013-02-15T23:32:56Z
dc.date.available2013-02-15T23:32:56Z
dc.date.issued1991
dc.identifier.urihttp://hdl.handle.net/10945/28384
dc.descriptionApproved for public release; distribution is unlimiteden_US
dc.description.abstractMultispectral imagery is used for the analysis of nighttime low clouds whose cloud top temperatures are similar to that of the ocean surface. At night AVHRR channel 3 (3.7 pm) and channel 4 (10.8 /^m) brightness temperature differences distinguish the presence of low stratus and fog from the ocean surface improving upon the channel 4 analysis alone. However, the effect of moisture attenuation in channel 4 offsets this temperature difference and impact thresholds which determine low cloud extent. Radiative transfer simulations using different moisture profiles helped to determine threshold adjustment. This thesis uses one of two sets of thresholds depending on moisture extent in an enhancement scheme to discriminate clear areas, and scattered, broken and overcast clouds on different summertime imagery cases over the ocean. Two cases are illustrated thoroughly and the technique was also applied to eight other cases. Results agreed for the most part with surface observations and visible GOES from the previous day. The multi-channel technique improved most or all deficiencies of the single channel analysis in all the cases except one where only some deficiencies were improved. The color enhancement provides a clear, qualitative picture of nighttime low cloud.en_US
dc.description.urihttp://archive.org/details/multispectralana00dyke
dc.format.extent42 p.;28 cm.en_US
dc.language.isoen_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, U.S. Code, section 101. Copyright protection is not available for this work in the United States.en_US
dc.titleMultispectral analysis of nighttime low clouds over the ocean.en_US
dc.typeThesisen_US
dc.contributor.secondreaderDavidson, Kenneth L.
dc.contributor.corporateNaval Postgraduate school
dc.contributor.departmentDepartment of Meteorology
dc.subject.authorLow cloud analysisen_US
dc.subject.authorRadiative transferen_US
dc.subject.authorFogen_US
dc.subject.authorSatellite imageryen_US
dc.description.serviceCaptain, United States Air Forceen_US
etd.thesisdegree.nameM.S. in Meteorologyen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineMeteorologyen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US


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